/*
 * Copyright (C) 2007 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.dx.rop.code;

import com.android.dx.rop.cst.Constant;

/**
 * Instruction which contains an explicit reference to a constant.
 */
public abstract class CstInsn extends Insn {

	/** {@code non-null;} the constant */
	private final Constant cst;

	/**
	 * Constructs an instance.
	 * 
	 * @param opcode
	 *            {@code non-null;} the opcode
	 * @param position
	 *            {@code non-null;} source position
	 * @param result
	 *            {@code null-ok;} spec for the result, if any
	 * @param sources
	 *            {@code non-null;} specs for all the sources
	 * @param cst
	 *            {@code non-null;} constant
	 */
	public CstInsn(Rop opcode, SourcePosition position, RegisterSpec result,
			RegisterSpecList sources, Constant cst) {
		super(opcode, position, result, sources);

		if (cst == null) {
			throw new NullPointerException("cst == null");
		}

		this.cst = cst;
	}

	/** {@inheritDoc} */
	@Override
	public String getInlineString() {
		return cst.toHuman();
	}

	/**
	 * Gets the constant.
	 * 
	 * @return {@code non-null;} the constant
	 */
	public Constant getConstant() {
		return cst;
	}

	/** {@inheritDoc} */
	@Override
	public boolean contentEquals(Insn b) {
		/*
		 * The cast (CstInsn)b below should always succeed since
		 * Insn.contentEquals compares classes of this and b.
		 */
		return super.contentEquals(b)
				&& cst.equals(((CstInsn) b).getConstant());
	}
}
